Bearing metal



UNITED STATES PATENT OFFICE.

anus e. KELLY. Annex: 1.. narrow, AND HOLMES ALL, or snmmm', nrssounr.

BEARING METAL.

No Drawing.

ALBERT L. PRINGLE, and HOLMES HALL,

citizens of the United States, residing at the city. of Sedalia, in the county of lf'ettis and State of Missouri, have invented certain new and useful Improvements 111 Bearing Metals, of which the following is a specification.

This invention consists of a bearing metal composed of zinc, aluminum, t1n, and lead, which composition is very close-gra ned and very tough and has enduring qualities and when turned, bored, planed, filed, or scraped will have a very smooth surface and w thstand very heavy pressure at a very h gh rate of speed and which wears away very slowly.

The zinc and aluminum are used as a base or to form the foundation of this hearing metal and to give hardness and toughness to the same. The zinc and aluminum are used in substantially equal proportions by we1ght or with a slightly greater percentage of one than the other, and in practice we have used a sli htly greater percentage of zinc than alummum, although we have also obtained very satisfactory results by using a slightly greater percentage of aluminum than zinc, and we have used the aluminum and zinc combined as constituting from 15 per cent. to 35 per cent. of the whole, the aluminum constituting from 5 per cent. to 15 per cent. of the whole and the zinc comprising from 10 per cent. to 20 per cent. of the Whole.

The union of zinc and aluminum creates a new alloy which is tougher, smoother, and closer-grained and causes less friction than either zinc or aluminum used separately.

The tin and lead are used to give the composition body and to overcome crystallization'and to avoid brittleness and to form a composition that will have a smooth surface and also to decrease and overcome friction. Sufiicient quantities of tin and lead should be used so that, when combined with the zinc and aluminum, the composition will have asmooth surface and will not crystallize and will not heat by contact with the other metals as when used as a bearing metal in a journal-bearing composed of steel or other metals when run at a very high rate of speed, and yet the tin and lead should not be used in such a proportion as will make the composition too soft,

Specification of Letters Patent. Patented Ap 26, 1921 Application filed May 7, 1920. Serial Ito. 879,642. i

but the aluminum and zinc should constitute a sufficient proportion of the whole to maintain hardness and toughness of the comp0s1tion. ,The lead serves, also, as a binder for the whole, which is a physical rather than a chemical union of ingredients. In our experiments .we have used tin and lead in substantially the proportions by weight of two parts of tin to one part lead, the tin .and lead constituting from 65 per cent. to 85 per cent. of the whole;

Our preferred formula is 48 per cent. tin, 24 per cent. lead, 16 per cent. zinc, and 12 per cent. aluminum, but we have found that this formula is susceptible to change and that in certain uses for hearing metal better results may be obtained by slightly changing our formula. When using our composition for bearings where the bearing surface is small and where the machinery is run at an excessive rate of speed, the proportion of tin can be slightly increased and the pr0-- portions of lead and aluminum slightly dei creased; and, on the other hand, when the bearing surface is lar e and only a mod erate speed is attaine the percentage of tin may be slightlygdecreased and the percentage of lead and aluminum and-even the percentage of zinc may be increased and equally good results obtained.

While the proportions-above given are, as stated, susceptible to some variation Without affecting or injuring the quality of this hearing metal, any substantial deviation'from the proportions given will impair theusefulness of the compound as a bearing metal. The bearing metal of the composition as above described is produced in the following manner:

First. Melt the aluminum and add the zinc to themelted aluminum, and as the zinc melts, keep stirringuntil all the zinc and aluminum are melted and thoroughly mixed; or melt the zinc and aluminum separately and pour the melted zinc and aluminum together and stir thoroughly until the two are well mixed. 7

Second. When the aluminum and zinc are melted and thoroughly mixed together, skim off the scum which forms on the top of this mixture with a strainer composed of some metal which will not melt from the heat of the melted zinc and aluminum.

Third. Add the lead and stir continuously until the lead is melted and mixed with the aluminum and zinc.

Fourth. Add the tin and stir the mixture continuously until all the tin is melted and the mixture is thoroughly mixed and then pour into molds ot' the form desired.

A characteristic result of the materials combined in the proportions stated is that the 1"Slllt:ll1t alloy is particularly adapted for use as a bearing metal. F or example, the combination of the zinc and aluminum gives that desired degree of hardness and touglmess to the alloy best adapted for its use as a bearing metal when used in substantially equal proportions by weight, and this desired condition is disadvantageously affected when these proportions are changed. Again, the tin and lead, substantially in the proportions mentioned afford a smooth surface to avoid excessive friction, and also avoid brittleness. If the proportions named are substantially departed from, experience has proven that crystallization and frictionheating will result. Hence the proportions named. both as to the relative part of each metal to the other and also to the Whole, are inost elfective for a bearing metal alloy, any substantial variation of such proportions resulting in a bearing metal having an undesirable characteristic for the particular use.

Having thus described this invention, we

hereby reserve the benefit of all changes in form, ar angement, order, or use of parts, as

it is evident that many minor changes may be made therein without departing from the spirit of this invention or the scope of the following claims:

\Ve claim:

1. A bearing -metal composed of tin, lead, zinc, and aluminum, substantially in the proportions of one part of aluminum, slightly more than one part of zinc, tWo parts of lead and four parts of tin.

2. A bearing metal composed of tin, lead, zinc, and aluminum, the zinc and aluminum constituting fromone-sixth to one-third vot' the whole in the proportions f one part of aluminum, and a slightly greater proportion of zinc, the remainder of the composition being composed of tin and lead substantially in the proportions of two parts of tin to one part of lead.

In testimony whereof We hereunto afiix our signatures.

JAMES Gr. KELLY. ALBERT L. PRINGLE. HOLMES HALL.

Witnesses:

J OHN J. KELLY, W. D. OBANNoN. 

